ENIGMA denotes any dark saying, wherein some well known thing is concealed under obscure language. The word is Greek, Ανίγματος, formed of ανίσταται, obscure innuere, to hint a thing darkly, and of αἴνιγμα, an obscure speech or discourse. The popular name is riddle; from the Belgic raeden, or the Saxon araethan, to interpret. F. Bouhours, in the memoirs of Trevoux, defines an enigma, a discourse or painting, including some hidden meaning, which is proposed to be guessed.